The present invention relates to a method and an apparatus for connecting a probe whose electrical connections end on a circuit board that can be introduced into a receptacle of a connector plug that comprises two half-shells which carry on sides facing one another the mating contacts for the connections of the circuit board and between them form a receptacle for the circuit board, the half-shells being held together under tension by way of a U-shaped spring which surrounds them.
The probe is connected to a connector plug to which, as a rule, a prefabricated wiring harness is already attached. The half-shells are often ceramic parts that can easily be damaged. Simply plugging the circuit board of the probe into the receptacle of the connector plug is therefore out of the question. The half-shells are under a compressive force, generated by the spring surrounding them, that upon introduction of the circuit board would need to be exerted on the spring via the half-shells and overcome. Since the ceramic half-shells are very brittle, forceful manual introduction of the circuit often results in damage to the half-shells and to the mating contacts, which are very sensitive to shifting movements especially if the overall geometry is very small (approx. 1 cm3) and the compressive force is very large. The spring can also be plastically deformed, since it has a very steep characteristic curve and can very easily be overextended.
It is an object of the invention to create a method and an apparatus of the kind mentioned initially in which the circuit board of the probe can be introduced into the connector plug with no risk of damage thereto or to the half-shells having the mating contacts, and which can be performed with no adverse effect on spring characteristics.
According to the present invention, the method is embodied in such a way that the connector plug is introduced between two displacing jaws and is positioned such that spreader extensions of the displacing jaws are directed toward the opening of the spring; that by opposite-direction displacement of the spreader extensions introduced into the opening of the spring, the spring is spread apart over a predefined displacement travel; that the circuit board is introduced into the receptacle, which can now be enlarged, between the half-shells; and that the circuit board is then, as a result of contraction and/or extension of the spreader extensions, held under tension between the half-shells of the connector plug by way of the released spring.
The displacement movements are preferably coordinated with one another in such a way that the movement by which the connector plug is introduced between the displacing jaws is limited by stops which define the positioning of the connector plug in the introduction direction; and that the displacing jaws are displaced parallel to the wide side of the receptacle between the half-shells of the connector plug; and that the spreader extensions, the positioning extensions, and the tracking extensions are respectively displaced in opposite directions, but parallel to the narrow side of the receptacle. For defined retention of the spring as it is spread, provision can also be made for the spring to be retained, on the side facing away from the opening, by way of a retaining extension of the displacing jaw.
The advantage of this feature is that it can be performed precisely with an apparatus; a very short cycle time can be achieved with the method steps, i.e. with the corresponding displacement of the displacing jaws. In addition, the method can also be used with a very small overall geometry, since the connector plug and spring in each case need to be brought into effective connection only via extensions of the displacing jaws. According to a particularly simple embodiment, provision can be made for positioning of the connector plug to be performed with positioning extensions of the displacing jaws that are introduced into positioning receptacles of the half-shells of the connector plug or are brought into contact against positioning surfaces of the half-shells, and are displaced synchronously with the spreader extensions of the displacing jaws.
If provision is made, according to a development, for the displacing jaws to be introduced with tracking extensions into associated tracking receptacles of the half-shells, or placed against tracking surfaces thereof, and for the opposite-direction displacement of the tracking extensions of the half-shells of the connector plug to track, in stress-free-fashion, the spreading of the spring, the receptacle is then enlarged automatically as the spring is spread and tracks the spring, but the half-shells are not pressed against the spring. Introduction of the circuit board into the receptacle of the connector plug is thereby facilitated, and damage to the circuit board or half-shells is prevented, even at very small dimensions.
The method according to the present invention can also be used to detach the probe from the connector plug. This is done by performing the method steps in the same sequence except that when the spring is spread, the circuit board of the probe is pulled out of the expanded receptacle between the half-shells of the connector plug before the spring is then released.
An apparatus for carrying out the method is characterized in that the displacing jaws are arranged on both sides of the connector plug and are movable toward and away from one another; that the displacing jaws comprise in each case a stack of plates, arranged one above another, on which the positioning extensions and spreader extensions are shaped on the sides facing one another; that the plates are displaceable in opposite directions perpendicular to the displacing movements of the displacing jaws, the plates displaceable in the one direction being equipped with a receiving orifice for a first displacement stud and the plates displaceable in the opposite direction being equipped with a receiving orifice for a second displacement stud; that the plates displaceable in the one direction have an elongated guide hole for the second displacement stud, and the plates displaceable in the opposite direction have an elongated guide hole for the first displacement stud; and that the displacement studs are arranged, as eccentric studs, on drive wheels that can be driven in opposite rotation directions.
The displacement studs that are movable toward or away from one another, which are arranged as eccentric studs on the two drive wheels, make it easy to achieve the opposite-direction displacement movements of the positioning and spreader extensions and transfer them to the half-shells and to the spring of the connector plug. Of course the plates can also have other extensions for gripping, grasping, moving apart, or bringing together other objects, and the apparatus can be used as a grasping tool for other applications.
According to an advantageous embodiment, provision is made for the drive wheels to be configured as gear wheels which are in engagement with one another and of which at least one is drivable.
In order to achieve an unimpeded opposite-direction displacement movement for the plates, the design is such that the elongated guide holes are oriented in the displacement directions of the plates, and have a longitudinal dimension which is greater than the maximum displacement travel of the plates.
Correct engagement of the positioning and spreader extensions against the connector plug that is to be processed is ensured by the fact that the positioning extensions and the spreader extensions and tracking extensions can be directed, within the stack height, toward the positions of the positioning receptacles or positioning surfaces on the connector plug introduced between the displacing jaws, and the spreader extensions can be directed toward the position of the opening of the spring.